Multiple events may have a metric_leader to aggregate into. This happens
for uncore events where, for example, uncore_imc is expanded into
uncore_imc_0, uncore_imc_1, etc. Such events all have the same metric_id
and should aggregate into the first event. The change introducing
metric_ids had a bug where the metric_id was compared to itself,
creating an always true condition. Correct this by comparing the
event in the metric_evlist and the metric_leader.

Fixes: ec5c5b3d2c21 ("perf metric: Encode and use metric-id as qualifier")
Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/perf/util/metricgroup.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/perf/util/metricgroup.c b/tools/perf/util/metricgroup.c
index 51c99cb08abf..1f1b78b0388f 100644
--- a/tools/perf/util/metricgroup.c
+++ b/tools/perf/util/metricgroup.c
@@ -314,7 +314,7 @@ static int setup_metric_events(struct hashmap *ids,
 		 */
 		metric_id = evsel__metric_id(ev);
 		evlist__for_each_entry_continue(metric_evlist, ev) {
-			if (!strcmp(evsel__metric_id(metric_events[i]), metric_id))
+			if (!strcmp(evsel__metric_id(ev), metric_id))
 				ev->metric_leader = metric_events[i];
 		}
 	}
-- 
2.34.1.703.g22d0c6ccf7-goog

On 15/01/2022 06:28, Ian Rogers wrote:
> Multiple events may have a metric_leader to aggregate into. This happens
> for uncore events where, for example, uncore_imc is expanded into
> uncore_imc_0, uncore_imc_1, etc. Such events all have the same metric_id
> and should aggregate into the first event. The change introducing
> metric_ids had a bug where the metric_id was compared to itself,
> creating an always true condition. Correct this by comparing the
> event in the metric_evlist and the metric_leader.
> 
> Fixes: ec5c5b3d2c21 ("perf metric: Encode and use metric-id as qualifier")
> Signed-off-by: Ian Rogers<irogers@google.com>
> ---

Looks ok and I quickly tested it:
Reviewed-by: John Garry <john.garry@huawei.com>